Research shows impact of nicotine vaping varies with age and sex

Close up on hands holding vape pensWhile vaping has become popular, researchers say methods to study the effects of inhaling vapour are limited. (Pexels/Olena Bohovyk)

By Prabhjot Sohal

Vapes or e-cigarettes were introduced as a potentially safer alternative to traditional smoking to curb tobacco use. However, the popularity of vapes has risen among an age group it wasn’t intended for: adolescents. 

While the entire breadth of the health effects of vaping is still being unveiled, previous research has shown one in four high school students in Canada have reported vaping in the preceding 30 days, with almost 12 per cent having reported exclusively using nicotine vapes. 

A new study, published in the journal Neuropsychopharmacology, examined the effects of nicotine vapour exposure in rat models to understand nicotine-induced reward and withdrawal behaviour, brain connectivity and how the body processes nicotine. 

The study, led by Jibran Khokhar, PhD, associate professor in the Department of Anatomy and Cell Biology, and graduate student and Vanier scholarship winner Jude Frie, has shown that factors of sex and age influence the body’s response to nicotine vapour. 

Jibran KhokharJibran Khokhar, PhD, associate professor, Anatomy and Cell Biology (Mac Lai/Schulich Medicine & Dentistry)

“By using the route of exposure and brain circuit assessment methods akin to those used in humans, the findings here can hopefully demystify the effects of nicotine vaping on the adolescent and the adult human brain, and the important role that sex plays in these effects,” said Khokhar, Canada Research Chair in Translational Neuropsychopharmacology. 

The study has shown adult female rats were more likely to acquire a liking for longer exposures to nicotine vapour, while female adolescent rats, as well as male adult and adolescent rats, did not show the same level of preference. 

Additionally, adult and adolescent male rats experienced symptoms of withdrawal and increased activity due to nicotine vapour exposure, while female rats did not exhibit these symptoms. 

The study also revealed that adult females had higher nicotine levels in their bodies and brains compared to adult males and adolescent females. 

“Brain connectivity in the nicotine-exposed rats was altered, indicating that vaping affects the brain differently depending on age and gender,” said Khokhar. Understanding these complexities is vital not only for addressing the risks associated with vaping but also for developing effective strategies to protect vulnerable populations, especially youth, from the potential harms of e-cigarette use. 

“This study also highlights the importance of being mindful of sex differences in drug disposition which would then alter the drug effects. Far too often, the same doses are used in both sexes but how much of the drug actually gets to the brain or blood is never tested,” said Khokhar. 

Open-source methods to study nicotine vapour effects 

While vaping has become popular, methods to study the effects of inhaling vapour are limited. The team of researchers led by Khokhar developed an open-source apparatus to conduct research on the behavioural and physiological effects of vaping, particularly in rodents.

Diagram showing design of the OpenVape systemDesign of the OpenVape system (supplied)

The apparatus, called OpenVape, is low cost and can be customized to work with various types of vaporizers. This includes not only e-cigarettes, but also other vaporizers designed for different substances such as nicotine pods, tanks, cannabis flowers or concentrates. 

“By using open-source tools like our OpenVape system, this type of study becomes accessible for researchers from various walks of life. Importantly, we hope by reducing the barriers to entry to perform this type of research, we can jumpstart additional lines of inquiry by other groups to learn more about this pressing topic with high public health relevance,” said Khokhar.